A typical fluidic oscillator includes a block or body which defines a power nozzle that produces a fluid jet. The jet is directed through a chamber toward the upstream edge of a flow splitter that forms the inner walls of a pair of oppositely inclined diffuser legs. The outer walls of the legs are formed by the body, and each leg leads to an outlet port. The jet will oscillate back and forth between the legs, rather than sticking to the walls of one of them, if so-called "spoiler" passages are used which extend from near the lower end of each leg to a respective side of the chamber. When the main jet flows through one of the legs, the spoiler passage for that leg feeds back some of the flow which enters the side of the chamber transversely and causes the main jet to switch over to the other leg. Then the spoiler passage on that side creates an opposite transverse flow into the side of the chamber, which switches the main jet flow back to the first leg. The switching occurs on a cyclical basis as a certain frequency. However, the spoiler passages that have been used are relatively long looping paths in the body which are difficult and expensive to manufacture, and most any structural defect therein will cause instability in the switching action and the frequency of operation of the transducer.
One object of the present invention is to provide a fluidic oscillator having new and improved means to cause stable switching.
Another object of the present invention is to provide a new and improved fluidic oscillator that uses a vacuum or negative pressure effect which pulls the jet back and forth across the upstream edge surface of the splitter to produce switching.
Still another object of the present invention is to provide a new and improved fluidic oscillator which eliminates the use of feedback loops and thus reduces size and manufacturing costs, and simplifies construction, while providing improved frequency stabilization.